999988886665 has 16 divisors (see below), whose sum is σ = 1265114517120. Its totient is φ = 756703918080.

The previous prime is 999988886569. The next prime is 999988886681. The reversal of 999988886665 is 566688889999.

It is not a de Polignac number, because 999988886665 - 2⁷ = 999988886537 is a prime.

It is a nialpdrome in base 10.

It is a self number, because there is not a number n which added to its sum of digits gives 999988886665.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8149869 + ... + 8271658.

It is an arithmetic number, because the mean of its divisors is an integer number (79069657320).

Almost surely, 2^999988886665 is an apocalyptic number.

999988886665 is a gapful number since it is divisible by the number (95) formed by its first and last digit.

It is an amenable number.

999988886665 is a deficient number, since it is larger than the sum of its proper divisors (265125630455).

999988886665 is a wasteful number, since it uses less digits than its factorization.

999988886665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16422192.

The product of its digits is 29023764480, while the sum is 91.

It can be divided in two parts, 999988 and 886665, that added together give a triangular number (1886653 = T₁₉₄₂).

The spelling of 999988886665 in words is "nine hundred ninety-nine billion, nine hundred eighty-eight million, eight hundred eighty-six thousand, six hundred sixty-five".